MAX1304ECM Maxim Integrated, MAX1304ECM Datasheet - Page 29

• Manufacturer Part Number: MAX1304ECM
• Description: Analog to Digital Converters - ADC
• Manufacturer: Maxim Integrated

Specifications of MAX1304ECM

• Number Of Channels: 8
• Architecture: SAR
• Conversion Rate: 1075 KSPs
• Resolution: 12 bit
• Input Type: Single-Ended
• Snr: 71 dB
• Interface Type: Parallel
• Operating Supply Voltage: 2.7 V to 5.25 V, 4.75 V to 5.25 V
• Maximum Operating Temperature: + 85 C
• Package / Case: LQFP-48
• Maximum Power Dissipation: 1818.2 mW
• Minimum Operating Temperature: - 40 C
• Number Of Converters: 1
• Voltage Reference: 2.5 V

8-/4-/2-Channel, 12-Bit, Simultaneous-Sampling ADCs
Table 7 and Figure 14 show the two’s complement trans-
fer function for the ±10V input range MAX1312/
MAX1313/MAX1314. The FSR is eight times the voltage at
REF. The internal +2.5V reference gives a +20V FSR,
while an external +2V to +3V reference allows an FSR of
+16V to +24V, respectively. Calculate the LSB size using:
which equals 4.88mV with a +2.5V reference.
Table 7. ±10V Bipolar Code Table
DIGITAL OUTPUT
0111 1111 1111 =
0111 1111 1110 =
0000 0000 0001 =
1000 0000 0001 =
1000 0000 0000 =
0000 0000 0000 =
1111 1111 1111 =
COMPLEMENT
with ±10V, ±5V, and 0 to +5V Analog Input Ranges
TWO’s
CODE
0x7FE
0x7FF
0x001
0x000
0xFFF
0x801
0x800
1
______________________________________________________________________________________
LSB
DIGITAL OUTPUT
EQUIVALENT
DECIMAL
(CODE
=
CODE
+2047
+2046
-2047
-2048
8
+1
-1
0
x V
2
10
12
)
REF
Bipolar ±10V Devices
INPUT VOLTAGE
(
+9.9976 ±0.5 LSB
+9.9927 ±0.5 LSB
+0.0073 ±0.5 LSB
-0.0024 ±0.5 LSB
-9.9927 ±0.5 LSB
-9.9976 ±0.5 LSB
0.0024 ±0.5 LSB
V
V
REF
MSV
(V)
= +2.5V
= 0V
)
The input range is centered about V
MSV = AGND, and the input is symmetrical about zero.
For a custom midscale voltage, drive MSV with an
external voltage source. Noise present on MSV directly
couples into the ADC result. Use a precision, low-drift
voltage reference with adequate bypassing to prevent
MSV from degrading ADC performance. For maximum
FSR, do not violate the absolute maximum voltage rat-
ings of the analog inputs when choosing MSV.
Determine the input voltage as a function of V
V
Figure 14. ±10V Bipolar Transfer Function
MSV
, and the output code in decimal using:
0x7FD
0x7FC
0x7FF
0x7FE
0x001
0x000
0xFFF
0x803
0x802
0x801
0x800
-2048 -2046
V
CH_
= LSB x CODE
INPUT VOLTAGE (V
-1 0 +1
8 x V
(MSV)
CH_
REF
10
- V
+ V
MSV
1 LSB =
IN LSBs)
MSV
MSV
+2045
. Normally,
8 x V
2
12
+2047
REF
REF
29
,